The naked man speaks again - ha ha
Have a good look at these links. No statements to be fund of RMS - IHF or anything. It would be interesting to know what this club of pro amplifier companies including Lab.Gruppen uses.
PowerSoft
Crown
Camco
Lab.Gruppen
Earlier days Lab.Gruppen stated both EIA and IHF, but those days are over and I don’t know who broke this tradition.
Powersoft K1o states 2 x 6000W with average consumption of 2300VA! Music has a crest factor of 10 -12dB!
Macro Tech
I-Tech
Crown uses in these two documents 1/8th pink noise to measure power consumption, for what it’s worth mentioning music has a crest factor of 10-12dB.
Have any of you tried to measure the average level and the crest factor of a music signal?
If you haven’t done it please do, because I have done it.
The meyersound solution looks okay and I know of this solution. I don’t know why Kenneth chose the crowbar solution, but I have never experienced any problem with it and if there had been a problem he would have change it. Unfortunately Kenneth has left Lab.Gruppen so I can’t ask him, but I’ll ask one of the service guys next time I come by the factory if they have made any service on the crowbar circuit. Let’s pretend that you were at a gig using a fP+10000Q driving bass and mid and that it had the meyer solution and you had a amp failure at one of the channels, then you would only be able to play music above 1kHz or so. I would prefer one channel blowing its rail fuses or if you say so also the driver, but the gig could go on.
Have a good look at these links. No statements to be fund of RMS - IHF or anything. It would be interesting to know what this club of pro amplifier companies including Lab.Gruppen uses.
PowerSoft
Crown
Camco
Lab.Gruppen
Earlier days Lab.Gruppen stated both EIA and IHF, but those days are over and I don’t know who broke this tradition.
Powersoft K1o states 2 x 6000W with average consumption of 2300VA! Music has a crest factor of 10 -12dB!
Macro Tech
I-Tech
Crown uses in these two documents 1/8th pink noise to measure power consumption, for what it’s worth mentioning music has a crest factor of 10-12dB.
Have any of you tried to measure the average level and the crest factor of a music signal?
If you haven’t done it please do, because I have done it.
The meyersound solution looks okay and I know of this solution. I don’t know why Kenneth chose the crowbar solution, but I have never experienced any problem with it and if there had been a problem he would have change it. Unfortunately Kenneth has left Lab.Gruppen so I can’t ask him, but I’ll ask one of the service guys next time I come by the factory if they have made any service on the crowbar circuit. Let’s pretend that you were at a gig using a fP+10000Q driving bass and mid and that it had the meyer solution and you had a amp failure at one of the channels, then you would only be able to play music above 1kHz or so. I would prefer one channel blowing its rail fuses or if you say so also the driver, but the gig could go on.
Attachments
TOINO said:Hmm...
What we need is a revolution on loudspeaker driver technology.
Don’t forget that more than 90% of the amplifier power is lost in heat.
Enclose a modern hi power bass loudspeaker is the equivalent to put a dry iron (http://en.wikipedia.org/wiki/Ironing) in a closed box.
PA horns are already 20% to 40% power efficient (105dB/W to 108dB/W figures, I own that stuff and I love it). Compact direct-radiator PA bass solutions also achieve efficiencies in the 105dB/W range through mutual coupling of several LF drivers (Electrovoice "manifold" and the like).
Hi-fi stuff is usually 0.5% power efficient (89dB/W, something I got tired of).
Workhorse said:
He's probably an audio salesman (the ones pretending to know more than anybody else, but with a sad truth behind...)
Concerning power consumption, I have actually measured it in a real gig with a freaky friend at the mixing console and the amplifiers clipping, and in average it's well below than 1/10th of total rated power. Amplifiers were QSC EX1600 and EX4000 (with active crossovers). Speakers were Turbosound 3-way, all horn loaded (2", 10", 18"), 16 enclosures. Measurement method was current transformer placed in mains supply to all amplifiers. It was really loud btw...
Re: The naked man speaks again - ha ha
Hi Robert GS
I thought that they not mention RMS power, because of this: http://www.eznec.com/Amateur/RMS_Power.pdf http://www.hifi-writer.com/he/misc/rmspower.htm , etc.
And I have nothing against REAL crowbar solution… only about kidding with crowbar.
“Meyer sound solution” is also a crowbar with relays…
Furthermore, crowbar is not instantaneous because you have the driver/integrator circuit.
Is about that that I am bloody irritated and is maybe why Kenneth chose to go away? An honest practical engineer annoyed by “multiplication of the Watts miracle” in the marketing department?
Let’s see a hold “half-honest” data sheet? http://www.crownaudio.com/pdf/legacy/103169.pdf
Page 35
Note that on the FTC Continuous Average they are missing values!
Guess why?
This continuous measurement represents the maximum per-channel power an amplifier can deliver over a five minute period.
FIVE MINUTS is too much for 2ohm load and the VZ5000 protects itself. So no FTC power…
Could sustain 4ohm at 1Khz but not full bandwidth…
And apparently at 8ohm load everything is ok.
I am not defending the FTC standard as a good one. Maybe 5 minutes is too much…
???????? Eva, please, conduct yourself!
Hi Robert GS
I thought that they not mention RMS power, because of this: http://www.eznec.com/Amateur/RMS_Power.pdf http://www.hifi-writer.com/he/misc/rmspower.htm , etc.
And I have nothing against REAL crowbar solution… only about kidding with crowbar.
“Meyer sound solution” is also a crowbar with relays…
Furthermore, crowbar is not instantaneous because you have the driver/integrator circuit.
Robert GS said:
Is about that that I am bloody irritated and is maybe why Kenneth chose to go away? An honest practical engineer annoyed by “multiplication of the Watts miracle” in the marketing department?
Let’s see a hold “half-honest” data sheet? http://www.crownaudio.com/pdf/legacy/103169.pdf
Page 35
Note that on the FTC Continuous Average they are missing values!
Guess why?
This continuous measurement represents the maximum per-channel power an amplifier can deliver over a five minute period.
FIVE MINUTS is too much for 2ohm load and the VZ5000 protects itself. So no FTC power…
Could sustain 4ohm at 1Khz but not full bandwidth…
And apparently at 8ohm load everything is ok.
I am not defending the FTC standard as a good one. Maybe 5 minutes is too much…
Eva said:
????????
Eva, please, conduct yourself!
Amp tech note
Please have a look at this PDF document. It has been on their homepage, but not any more. The link will die very soon.
Important parameters for a pro amp
I could talk a lot more about Kenneth + others and ......... + new owners, but I better leave it.
Now I really have to stop ... don’t haunt me…………
Please have a look at this PDF document. It has been on their homepage, but not any more. The link will die very soon.
Important parameters for a pro amp
I could talk a lot more about Kenneth + others and ......... + new owners, but I better leave it.
Now I really have to stop ... don’t haunt me…………
Hi Eva
Considering your discourtesy and moderators distraction, I have thinking twice.
However they are a few technical aspects in your last post that needs clarification and shows your lack of understanding.
At least you need to update your knowledge about the way your PA system works.
First, your PA horns use plain loudspeakers inside (and Hi freq. drivers). So you have also “dry irons” in boxes. If you don’t believe, measure their temperature at the end of your Castanet show. http://en.wikipedia.org/wiki/Castanets
Second, Turbosound has no such thing as horn loaded 18” cabinet. It is a “special” band-pass box.
It is not necessary to “know more than anybody else” to knows that the “Turbo horn” size is not enough to work as a horn in low frequencies.
You just need to know the basics and made some arithmetic’s…
Here is the original Anthony Andrews patent for your clarification: http://www.pat2pdf.org/patents/pat4215761.pdf
It seems that Anthony himself doesn’t understand their invention at the time.
On 40- page3 it says “although the reasons for this are not fully understood” (the efficiency)
Third, the EV “manifold” box is another plain band-pass box! Are you pretending a “multiplication of the dB miracle” with this box?
Here you have the patent: http://www.pat2pdf.org/patents/pat4733749.pdf
As anybody skilled in the art could see, is fundamentally a band-pass loudspeaker.
Their efficiency is roughly the some of equivalent individual loudspeaker boxes, prefacing the some quantity of loudspeakers, if you put them close enough for coupling at concern wavelengths.
And finally the way you have measured the average consumption in your Castanet show, implies that you have all the amplifiers on the same electrical mains supply phase, or monophasic connection.
Any average sound technician would tell you that is bad practice such a connection on so many power amplifiers.
I strongly recommend you to observe the amp racks of real concert professionals…
Considering your discourtesy and moderators distraction, I have thinking twice.
However they are a few technical aspects in your last post that needs clarification and shows your lack of understanding.
At least you need to update your knowledge about the way your PA system works.
First, your PA horns use plain loudspeakers inside (and Hi freq. drivers). So you have also “dry irons” in boxes. If you don’t believe, measure their temperature at the end of your Castanet show. http://en.wikipedia.org/wiki/Castanets
Second, Turbosound has no such thing as horn loaded 18” cabinet. It is a “special” band-pass box.
It is not necessary to “know more than anybody else” to knows that the “Turbo horn” size is not enough to work as a horn in low frequencies.
You just need to know the basics and made some arithmetic’s…
Here is the original Anthony Andrews patent for your clarification: http://www.pat2pdf.org/patents/pat4215761.pdf
It seems that Anthony himself doesn’t understand their invention at the time.
On 40- page3 it says “although the reasons for this are not fully understood” (the efficiency)
Third, the EV “manifold” box is another plain band-pass box! Are you pretending a “multiplication of the dB miracle” with this box?
Here you have the patent: http://www.pat2pdf.org/patents/pat4733749.pdf
As anybody skilled in the art could see, is fundamentally a band-pass loudspeaker.
Their efficiency is roughly the some of equivalent individual loudspeaker boxes, prefacing the some quantity of loudspeakers, if you put them close enough for coupling at concern wavelengths.
And finally the way you have measured the average consumption in your Castanet show, implies that you have all the amplifiers on the same electrical mains supply phase, or monophasic connection.
Any average sound technician would tell you that is bad practice such a connection on so many power amplifiers.
I strongly recommend you to observe the amp racks of real concert professionals…
Turbosound TMS-4 (now discontinued). See the hyp/exponential bass horn at the bottom. Effective length is roughly 1m, 1/4th wavelenght of 85Hz (it's heavily shrunk but that's not a problem when used in groups of 8 due to mutual loading):
In general you have a lot to learn, not only about electronics but about acoustics and practical PA.
The efficiency of plain loudspeakers is boosted to 20%-40% when the apparent mass of air in front of the diaphragm is made heavy enough to compete with the own moving mas of the driver. That's how horn loading (or mutual loading) works. Study horn theory.
The same phenomena happens when several direct radiating LF drivers (or bandpass boxes) are placed in close proximity (also happens for several shrunk bass horns intended to be used in groups). Didn't you know that in general terms the LF efficiency is boosted by 3dB/W when two speakers are placed together?
Single phase power was employed because they liked it that way (and measurement was a lot easier).
Nothing to sell here btw.
An externally hosted image should be here but it was not working when we last tested it.
In general you have a lot to learn, not only about electronics but about acoustics and practical PA.
The efficiency of plain loudspeakers is boosted to 20%-40% when the apparent mass of air in front of the diaphragm is made heavy enough to compete with the own moving mas of the driver. That's how horn loading (or mutual loading) works. Study horn theory.
The same phenomena happens when several direct radiating LF drivers (or bandpass boxes) are placed in close proximity (also happens for several shrunk bass horns intended to be used in groups). Didn't you know that in general terms the LF efficiency is boosted by 3dB/W when two speakers are placed together?
Single phase power was employed because they liked it that way (and measurement was a lot easier).
Nothing to sell here btw.
lumanauw said:
It's nicely sized to satisfy practical PA average power requirements. That's something difficult to explain to anybody not understanding how that stuff is used in practice. I love the resulting weight and size too. The whole point of switchmode technology in PA amplification is weight and size reduction.
Another example of practical engineering is one of my current projects. It's a class D amplifier that is required to produce +/-150V on a load as low as 5 ohms (4.5KW peak). To make it funnier, it must be small, light weight and portable, and it has to be fed both from a 10Ah deep cycle lead-acid battery of from mains (with built-in charging electronics). How is that possible? Well, the signal being amplified is going to be 50Hz-5Khz pink noise (with 12dB crest power factor or so) and it's only going to be used during 10 minutes or so before recharging. The load impedance also makes things easier (see attached picture, 5 ohms per vertical div)...
Attachments
It could be designed for audio but I'm making too much compromises here. Actually the amplifier is intended to be part of a very powerful soundproofing performance measurement system. Frequency response is limited due to the topology that I use and because I want a low switching frequency (48-96Khz at the expense of fidelity) and a filter with a low resonant frequency. The output filter is actually intended to resonante with the inductive load to produce some boost in the top octave (required for flattening). The PSU is also compromised because 4500W peak with 12dB crest factor translates into just 280W average power consumption, but music tends to have somewhat lower crest factors.
It's very application specific, the whole system is required to produce in excess of 125dB peak of 100Hz-5Khz pink noise onmidirectionally for long enough time for the measurements to be performed.
It's very application specific, the whole system is required to produce in excess of 125dB peak of 100Hz-5Khz pink noise onmidirectionally for long enough time for the measurements to be performed.
Eva
I have a lot to learn about everything, as you too.
Horn theory alone, doesn’t justify the Turbo low freq. efficiency. Try to apply the formulas, if you know them, and see what I mean.
Also try to remove the front camera volume (band-pass resonator) and all the efficiency is gone!
Also analyse the impedance curve: Nothing to do with a horn, everything to do with a pass-band.
Come on… horn is just an impedance adapter, and bass loudspeakers, viewed as pistons increase acoustic pressure in groups, simply because their total surface increases. Pressure = surface x displacement.
Nothing to sell here?
And what about your self-promotion?
I remember you criticised other members by doing the some…
Take a look at the attached picture. These junk it is what they are injecting directly on the amplifier rails.
Scope probes are 10x.
Is that ugly thing that you appreciate as good practical engineering? How should this amplifier sound with this kind of supply?
I have a lot to learn about everything, as you too.
Horn theory alone, doesn’t justify the Turbo low freq. efficiency. Try to apply the formulas, if you know them, and see what I mean.
Also try to remove the front camera volume (band-pass resonator) and all the efficiency is gone!
Also analyse the impedance curve: Nothing to do with a horn, everything to do with a pass-band.
Come on… horn is just an impedance adapter, and bass loudspeakers, viewed as pistons increase acoustic pressure in groups, simply because their total surface increases. Pressure = surface x displacement.
Nothing to sell here?
Eva said:
And what about your self-promotion?
I remember you criticised other members by doing the some…
Eva said:
Take a look at the attached picture. These junk it is what they are injecting directly on the amplifier rails.
Scope probes are 10x.
Is that ugly thing that you appreciate as good practical engineering? How should this amplifier sound with this kind of supply?
Attachments
This waveform that you call junk is carefully shaped to exhibit exactly the same average value as the own audio signal, so it does not produce any distortion, it only adds carrier residuals to the output, 630Khz (or whatever) and its harmonics. This is the trick. You are telling us that you don't understand switching mode electronics at all, and as a result, you just hate it, you call it junk and you discard it (typical human behaviour).
There is nothing wrong with shaping audio signals through high frequency carriers and integrating the HF stuff back to get the audio stuff. Rail modulation is actually a nice thing because output devices are operating at constant Vce at audio frequencies and this makes them more linear.
There is nothing wrong with shaping audio signals through high frequency carriers and integrating the HF stuff back to get the audio stuff. Rail modulation is actually a nice thing because output devices are operating at constant Vce at audio frequencies and this makes them more linear.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.